It is known in the art to provide a shutter mechanism for moving a shutter blade or other such component between spaced apart first and second end positions by magnetic force. For instance, electromagnets have been used to move a shutter blade between a first position which allows light to pass through an unshuttered aperture, to a second position which prevents the passage of light through the aperture. However, when such devices are to operate in a zero gravity environment or in an environment at reduced temperatures including cryogenic temperatures (down to 1.2K.), because of the extremely cold temperatures, no devices have been found to perform or function successfully until now.
Engineers and scientists at NASA working in the area of technology related to satellites and spacecraft that use optical elements such as mirrors or detectors for cryogenic infrared telescopes and cameras have long sought a test device in which they could check to assure that the mirrors had an accurate and stable surface figure at cold operating temperatures. In the past mechanical shutter systems have been utilized for that testing; however, the mechanical shutter systems had to pierce or be installed through the shell of an evacuated cryogenic dewar that was used for conducting such tests. The mechanical shutter systems also had to pierce various internal cryogenic shields such as liquid nitrogen and helium shrouds. This posed many problems with maintaining an adequate vacuum due to vacuum component leaks, and also maximizing the cooling of the dewar because of the lack of an adequate thermal isolation which causes an increase in coolant boil-off. In addition, the mechanical feed through components tended to stick or lock and malfunction at low temperatures. Installation of the mechanical feed through components also required difficult and expensive system assembly and disassembly. The electrically actuated, magnetically operated cryogenic shutter disclosed herein eliminated the many problems associated with the mechanical shutter system.